Rectifier terminal device



April 1949- R. T. CHEESEMAN in" AL ,4

RECTIFIER TERMINAL DEVICE Filed March 21, 1945 I nve htow s: Ralph FCheeseman, Edgar A.Har-ty, 0

Their Attorney. Q

Patented Apr. 19, 1949 2,467,811 RECTIFIER TERMINAL DEVICE Ralph T.Cheeseman, Lynn, and Edgar A. Barty,

Marblehead, Mass., assignors to General Electriccompany, a corporationof New York Application March 21, 1945, Serial No. 533,930

2 Claims. (01. 175-366) The present invention provides a mounting, orterminal assembly, for electric blocking layer or so-called metallicrectifiers, such, for example, as selenium or copper oxide rectifiers.The terminal assembly provided by the present invention is particularlyWell adapted to mechanically secure and provide terminal connections forsmall rectifier cells.

Selenium rectifier cells, as described, for example, in Hewlett U. S.Patent 2,334,554, patented November 16, 1943, comprise a metal base,constituting one electrode, on which is applied a .layer of selenium.The surface of the selenium selenium type or other small metallic type,should be so mounted between terminals of electrical apparatus of whichthey form a part, that accidental displacement of the cells issubstantially precluded.

Our present invention provides an assembly for securing one or morerectifying cells together with electric terminals therefor and provides'means for so looking the cooperating parts in assembled relation as topractically preclude displacement during service, even when therectifying cells are very small.

A terminal assembly embodying our invention is shown in the accompanyingdrawing in which Fig. 1 is a vertical section of the assembly; Fig. 2 isa plan view partly in section; Fig. 3 is a magnified vertical section ofa rectifier cell; Fig. 4 is an exploded view of the entire assemblymember; Fig. 5 is a vertical section and Fig. 6 is a top view of amodification.

The selenium cell shown in Fig. 3 on an enlarged scale comprises adisc-shaped conductive base I, which'may consist of aluminum, iron orother suitable metal. successively superimposed on the base I are layersof selenium 2 and a nonconductive material 3. The latter may consist ofpaper impregnated with a resin, such as polystyrene. The insulation 3 isprovided with a central aperture, as indicated, through which theselenium film beneath it is exposed. The selenium film may be preparedas described in Hewlett Patents 2,334,554 and 2,354,521. A blockinglayer on the selenium (not shown) may be produced by treatment withhydrogen peroxide as described in Hewlett Patent 2,334,622. Acounter-electrode 4, which may consist of an alloy of tin and cadmium issuperimposed on the cell by spraying the liquid alloy over the entiretop surface of the cell, thereby making electrical contact with theselenium film through the orifice. The cell is formed by passage ofcurrent, as well understood.

A single completed cell 5 and cooperating parts are illustrated in Fig.4 and, as shown in connection with Fig. 5, a plurality of cells may beso mounted. Current connection may be made to the base I by a flatspiral 6 formed by coiling the conductor 1 near its end. Contact withthe counter-electrode 4 is made by a similar fiat spiral 8 constitutingpart of a conductor 9. In place of the spirals 6 and 8 any plate-likecontact members having a configuration conforming with the surfaces ofthe rectifier cell may be provided. As best shown in Fig. 1, thebent-over ends of the conductors I and 9 project outwardly substantiallynormal to the planes of the spirals 6, 8 As best shown in Fig. 1, theprojecting spur I0 formed by the projecting end of the conductor Iengages with a perforation l0 in the flat end wall of a clamp II. Theprojecting spur I2 of the conductor 9 engages with a perforation in aninsulating washer l3, which may consist of fiber or of a suitablephenolic resin composition.

When thus assembled, the parts ar confined in fixed relation by bendingthe projecting prongs l4 of the clamp II over the assembly to bind theassembled parts, as indicated in Figs. 1 and 2. The rectifier cell andcontact spirals thus are anchored and restrained by the interlocking ofadjacent members against lateral motion and disengagement from properlyassembled position. The insulating disk I3 prevents electrical contactof the spiral 8 with the clamp II which is in electrical contact withthe spiral 6.

As shown at Fig. 1, the assembled parts finally are embedded in a massl5 of a wax, or a resin, or other suitable easily fusible,non-conductive material which further ensures against loosening anddisengagement of the assembled parts. The coating also protects therectifier and contact from adverse climatic conditions which mightproduce corrosion.

, In the modified structure shown in Fig. 5, a conductor 16, the end ofwhich is coiled into the form of a flat spiral l'l, passes through aninsulating disk- [8; another conductor 19, the end of which is coiledinto a spiral 20 passes through an insulating disk 2|. Between the fiatspirals are located two selenium cells 22, 23. A single selenium cell,or greater number of cells, may be similarly mounted. in thismodification two clamps 24, 25 are provided, each clamp having prongs 26(the top set being shown in Fig. 6) which are bent over and engage withthe insulating disks l8 and 2|. The interior surface of the clamps 24,25 may be provided with an insulating varnish coating as indicated inFig. 5. Although not so indicated in the drawing, the modification ofour improved assembly shown in Figs. and 6 also may be encased in wax orresin.

What we claim as new and desire to secure by Letters Patent of theUnited States, is:

1. A rectifier assembly comprising a discshaped current rectifier cellhaving planar electrodes on opposite surfaces thereof, a pair ofelectric conducting terminal members engaging said electrodes and eachcomprising an elongated conductor having a planar spirally coiledportion and a central axial spur portion projecting substantiallyperpendicular to the plane of said spiral portion, said spirally coiledportions engaging said surface electrodes respectively in fiatwiserelation, 9, disc-shaped insulator overlying one said coiled terminalportion and having a central aperture coupled to the associated axialspur portion in interlockin relation, and a metallic clamping memberhaving a perforated end wall overlying the other said coiled terminalportion and coupled to the associated axial spur portion in interlockingrelation, said clamping member having a plurality of prongs extendingfrom said end wall and engaging said insulator in clamping relation,thereby to hold said rectifier and said terminals in assembled relation.

2. A rectifier assembly comprising a discshaped selenium rectifier cellhaving electric conducting surfaces on opposite sides thereofconstituting electrodes, a pair of terminal members engaging saidelectrodes and each comprising an elongated electric conductor having aplanar spirally coiled portion and a central axial spur portion, saidspirally coiled portion engaging a major portion of the area of saidsurface electrodes respectively in flatwise relation, a discshapedinsulator overlying one said coiled terminal portion and having acentral aperture coupled to the axial spur portion of said one terminalin interlocking relation, a metallic clamping member having a perforatedend wall overlying the other said coiled terminal portion and coupled tothe axial spur portion of said other terminal in interlocking relation,said clamping member having a plurality of prongs extending from saidend wall and bent over said insulator in clamping relation thereby tohold said rectifier assembly and said terminals in assembled relation,and a mass of fusible insulating material encasing said entire assemblyand filling the interstices of said enumerated cell, terminal members,clamping member and insulator, thereby to mold said rectifier assemblyinto an integral completely insulated unit.

RALPH T. CHEESEMAN. EDGAR A. HARTY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,649,081 Rudolph Nov. 15, 19271,809,925 Edwards June 16, 1931 1,831,092 Bowles Nov. 10, 1931 1,839,431Webster Jan. 5, 1932 1,905,525 Strabel Apr. 25, 1933 1,961,825 HartyJune 5, 1934 1,973,039 Benedek Sept. 11, 1934 2,106,344 Flegal et alJan. 25, 1938 2,117,020 Conrad May 10, 1938 2,178,969 Ruben Nov. 7, 19392,223,172 George Nov. 26, 1940 2,235,640 Kresge Mar. 18, 1941 2,261,618Esseling et al Nov. 4, 1941 2,309,081 Priessman Jan. 26, 1943 FOREIGNPATENTS Number Country Date 234,281 England May 28, 1925 652,755 FranceMar. 13, 1929

